Electrical switches are frequently employed in sensing or interlock circuits. These switches are usually of relatively small size and include a movable actuator, or plunger, disposed in the path of a movable object. When the switch actuator is contacted by the object, the switch condition changes, i.e., from open to closed or from closed to open. The change in condition is sensed to provide an indication or to cause some further operation to occur.
In the usual case, much care must be taken to properly adjust the location of the switch body with relation to the path of movement of the object to be sensed. In some conditions, the consequences of maladjustment, either due to poor initial adjustment or to loss of adjustment during operation, can be extreme. For example, switches of this sort are employed in military vehicles and airlines for a variety of purposes. These applications require that the switch be precisely mounted and mechanically adjusted to provide the proper set point during initial installment. During subsequent use, environmental conditions might cause loss of adjustment. With a typical switch readjustment required returning to the site of the switch to mechanically readjust the position. Depending on the location, this might be a very difficult operation and require extended down time.
In some applications it is desirable to sense multiple discrete conditions of the movable object. With prior switches this requires that a separate switch be provided for each position. Each must be separately adjusted and readjusted to satisfy operational requirements.
While the problems discussed above are particularly apparent relative to sensing applications, such as a limit switch, the problems also exist in other applications, such as use of non-contact proximity sensors, pressure transducers and the like.
The present invention is directed to overcoming one or more of the problems discussed above in a novel and simple manner.